The research proposed herein aims at developing and utilizing a multimodal imaging approach to examine the underlying brain mechanism Involved in auditory attention. The proposed approach is to conduct the same experiment using functional magnetic resonance Imaging (fMRI) and magneto/electroencephalography (M/EEG). This powerful combination utilizes the fine spatial precision of fMRI with the high temporal resolution of M/EEG to map the spatiotemporal dynamics of the cortical networks associated with auditory attention and scene analysis. Currently, however, the acoustical noise associated with fMRI presents a technical hurdle to ail auditory studies. Initial steps to characterize the acoustical noise associated with different fMRI pulse sequences are underway. During the mentored phase, the candidate will draw on his signal processing expertise to develop a noise masking protocol that will psychoacoustically control for the auditory environment during fMRI scanning while mitigating the technical challenges In MR image reconstruction associated with the proposed auditory-amicable fMRI pulse sequence. In later stages, two experiments will be carried out examining how the prefrontal cortex is differentially involved when subjects are directed to attend different cues of the auditory stimulus. We will determine what "biomarkers" can be extracted from the M/EEG signals that are associated with the listener's attentional states. The project fits the candidate's long-term career goal of establishing a high-quality independent research program that combines engineering and neuroscience approaches in a synergistic manner to characterize the "biomarkers" that are associated with auditory scene analysis. This is clinically relevant because hearing aid users currently cannot understand speech easily in an acoustically crowded environment. Attention as "biomarkers" may one day be used to integrate with a processor that selectively amplify signal of Interest In real-time, actively aiding the listeners with auditory signal segregation. This work will facilitate the candidate's immediate goals of becoming an expert in multimodal imaging while bringing to the field his knowledge in speech and hearing sciences, particularly his quantitative psychophysics training. The mentored phase will be performed at the MGH-Harvard-MIT Martinos Center for Biomedical Imaging. The candidate will take advantage of the cutting-edge MRI facilities and expertise at the Center, as well as the world-class educational opportunities at its collaborating institutions. His career development plan includes training in MR data acquisition;consultations with experts of the field;coursework in image reconstruction in MRI and neuroengineering;participation in seminars and scientific meetings. As part of launching his own independent research program, the candidate will mentor a graduate student who will be expected to contribute to this project.